Numerical modeling of time-dependent cosmic-ray advection and diffusion in spherically symmetric wind bubbles shows escaping spectra harder than E^{-2} during the wind-driven phase, with low-energy suppression depending on the turbulence model.
Charged particle diffusion in isotropic random magnetic fields
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
The investigation of the diffusive transport of charged particles in a turbulent magnetic field remains a subject of considerable interest. Research has most frequently concentrated on determining the diffusion coefficient in the presence of a mean magnetic field. Here we consider diffusion of charged particles in fully three-dimensional isotropic turbulent magnetic fields with no mean field, which may be pertinent to many astrophysical situations. We identify different ranges of particle energy depending upon the ratio of the Larmor radius of the charged particle to the characteristic outer length scale of the turbulence. Two different theoretical models are proposed to calculate the diffusion coefficient, each applicable to a distinct range of particle energies. The theoretical results are compared with those from computer simulations, showing good agreement.
fields
astro-ph.HE 2years
2026 2verdicts
UNVERDICTED 2representative citing papers
Simulations show that drift dominance over diffusion can create a knee at PeV energies if parallel diffusion becomes energy-independent above 1 TeV, though some setups fail to match observed grammage.
citing papers explorer
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Time-dependent cosmic-ray escape from wind bubbles: hard spectra formation
Numerical modeling of time-dependent cosmic-ray advection and diffusion in spherically symmetric wind bubbles shows escaping spectra harder than E^{-2} during the wind-driven phase, with low-energy suppression depending on the turbulence model.
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Transition from Diffusion to Drift-Dominated Cosmic Ray Transport and the Origin of the Knee
Simulations show that drift dominance over diffusion can create a knee at PeV energies if parallel diffusion becomes energy-independent above 1 TeV, though some setups fail to match observed grammage.